The products of general formula (II) in which R represents a phenyl radical correspond to taxol and to 10-deacetyltaxol, and the products of general formula (II) in which R represents a tert-butoxy radical correspond to those which are described in European Patent EP 253,738.
The products of general formula (II), and especially those which occur in the 2'R,3'S form, possess especially advantageous antitumour and antileukaemic properties.